1. Department
of Biochemistry, Stanford University, Stanford, California 94305, United States
2. Advanced
Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
3. Department
of Radiology, Stanford University, Stanford, California 94305, United States
4. Department
of Chemistry, Stanford University, Stanford, California 94305, United States
5. Stanford
ChEM-H, Stanford University, Stanford, California 94305, United States